Folding apparatus and method



July l2, 1938. M, M, BALSAM 2,123,175

FOLDING APPARATUS AND METHOD Filed May 2o, 1936' 7 sheets-sheet 1 *Fla-1.,

ATTORNEY July 12, 1938. M M BALSAM V2,123,175

FOLDING APPARATUS AND METHOD Filed May 20, 1956 7 Sheets-Sheet 2 M. M. BALSAM FOLDING APPARATUS AND METHOD July 12, 1938.

Filed May 20, 1936 7' Sheets-Sheerl 3 INVENTOR ff M ATTORNEY July l2, 1938. Ml M, BALSAM' y l 2,123,175

FOLDING APPARATUS AND METHOD Filed May 20, 1936 7 Sheets-Sheet 4 FIGA.

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FOLDING APPARATUS AND METHOD Filed May 20, 1936 7 Sheets-Sheet 6 INVENTOR www i ATTORNEY July 12, 1938. M. M BALSAM 2,123,175

FOLDING APPARATUS AND METHOD Filed May 20, 1936 7 Sheets-Sheet '7 u" r \\\\\\\\\h ///////////////////////////////////,Il

INVENTOR Zvw w19- Patented July 12, 1938 UNITED sTATEs 2.123.115 y sommo.v Armas'rus AND smrnon Maurice M. Balsam, New York, N. Y., assignor to William L. Lawson, New York, N. Y.

' Application May 20, 1936, Serial No. 80,683

24 Claims. (Cl. 93-391) This invention relates to novel apparatus and method for folding a blank of sheet material and v more particularly to apparatus 'and method for folding a hollow blank of sheet material to form f said blank into a bellows.

One object of my invention is to fold the material into a form such as a. bellows, rapidly and accurately along predetermined lines. l

A further object of my invention is to provide tion will be apparent from the following descrip-v tion of one embodiment thereof illustrated in the drawings, in which Fig. 1 is an elevation of the left side of a com plete machine for performing the folding operations.

Fig. 2 is a horizontal sectional view illustrating the head of the machine in plan on an enlarged scale and taken on the line 2-2 `of Fig. 1.

Fig. 3 is a vertical section taken diagonally through the head of the machine on about the line'3-3 of Fig. 2 with certain parts broken away to better illustrate the construction.

Fig. 4 isa verticalA section, similar to Fig. 3, but showing the movable parts of the head of the machine in `an intermediate position.

Fig. 5 is a view similar to Figs. 3 and 4 but showing the folding mechanism in the position, occupied at the completion of the folding operation, and before release.

Fig. 6 is' a horizontal section taken on about the line 6-6 of Fig. 3.

Fig. 7 is a foreshortened vertical section of one detail of the mechanism taken on the line 1--1 of Fig. 3.

Fig. 8 is a horizontal sectional view of the mechanism illustrated in Fig. 'l and taken on the line 8--8 of Fig. 3.

Fig. 9 is a perspective view of a blank of material suitable for folding to form a camera bellows. Y

Fig. 10 is a vertical section of certain operating portions of the machine and the blank in an intermediate position at the start of the folding operation.

Fig. 11 is a view similar to Fig. 10 illustrating the machine parts'and the blank at a subsequent stage in the folding operation.

Fig. 12 is a View similar to Figs. 10 and 11 but showing the blank and machine parts at the completion of the folding operation.

Fig. 13 illustrates the position of the blank with respect to the machine after release thereof.

Fig. 14 illustrates the completely folded bellows.

Referring to the drawings, the folding machine is supported by a suitable frame I5. provided with a plate I. for supporting the folding mechanism, which may be attached to the frame by suitable means, such as bol-ts Il. Mounted on plate IG in a suitable manner, as by bolts, are a plurality of guides I8 arranged diagonally of the plate and providing four guide-ways for the slides I9. These slides I3 may be prevented from upward movement by fitting into the grooves provided between the plate It and the overhanging lips |8a of the guides Il (Fig. 7). The outer ends of the slides I9 may be provided with openings 2li drilled therein to receive one end of the springs 2 I. The main portions of these springs 2| may be supported in suitable casing members 22 attached to the corners -of the plate IB by means of the bolts 23. Bolts 24 may be provided in the ends of these casing members 22 for bearing against the outer ends of springs 2| to adjust the effective pressure thereof on the slides I8.

Slides I3 are preferably provided with camming means for restraining their movement toward the center of plate i8 under the action of springs 2|.' Such means may comprise rollers 25 rotatably mounted on shafts 28, the ends of which are held in the slides I9. 'Ihe lopenings 2l in the slides I9 are preferably suillciently large to freely support the rollers 25 and to receive the upper ends of the cam rods 28 having camming surfaces 28a which, Ain their normal position, serve to retract the slides I9 against the action of the springs 2|.

^ The inner ends of slides I9 may be each pro vided with a pair of fixed upwardly extending guide arms 29 which are recessed, as at 30, to form vertically extending grooves. Depending arms 3| may also be carried by the slides I9 and channeled as at 3|a to form extensions of said grooves. Mounted for vertical movement in each of these grooves are a series of three vertical plates 32, 33 and 34 of varying lengths, held in place by the reticulated plates 29a. fixed to the arms 29 and bythe plates y39 fixed to depending arms 3|. Plates 34, which are much longer than the others, are provided with horizontal sections 35 to which are attached the upper folding plates 36. Additional folding plates 3l and 38 may be attached to the top of guide plates 33 and 32, respectively.

rlhe lower ends of the springs @d are attached to the lowermost portions of plates 3d and the other ends of these springs may be ilxed to the depending arms 3l, thus normally serving to hold the guide plates 3; and the folding plates 3d in an elevated position. Pins il may be xed to plates Sti in a suitable manner to register in the notches it in the lower portion oi plates 32 and in order to also lift these plates to their uppermost position by the action oi springs db. Plungers d3 may also be mounted in the slides it and are normally urged -forward by the action oi springs These plunge-rs d3 may' be provided arms 33a for cooperation with sides or" die block All, as hereinaiter described.

Except for the shapes of the inwardly extending ends of the plates lll and lill, which are varied tor different folding actions, each slide ifi the mechanism which it supports is the same and they have, therefore, been described generally without referring to any specific one oi 'the Mounted centrally between these four slides 'lll and the series of plate members carried thereby is a mandrel comprising a vertically movable rod d5, one end of which passes through an opening in the strap d@ attached to underneath surface oi plate lli; the intermediate portion of rod d5 passes through the die block il tightly fitted in an opening in plate it. The top portion of rod l5 may be provided with. an end il@ of smaller cross section than the remainder of the rod for a purpose to be described hereinafter, a pair o concentric sleeves carrying the rectangular shaped plates di, 52, may be mounted concentrically with and between the rod and the die block fil. Rod and these sleeves and 5B are preferably provided with slots bfi, and 55, respectively, or". riterent lengths, to allow vertical movement thereof with respect to the pin be fixed in the die block. Fin 56 serves to prevent rotation of the rod and sleeves d@ and till. The lower portion of these sleeves @d and 5@ may be provided with suitable collars i'l and 5d, respectively, and the rod ttl may be provided with a xed collar 5d. Spring 5Fl, acting against collar 59, thus serves to hold the rod ad and plates 5l and. 52 spaced apart in their uppermost position.

Cam rods 28, for operating slides lil, are mounted for vertical movement within the sleeves di, fixed in the plate lil. These cam rods may be provided with collars Si@ to limit upward movement hereof. The springs 63 surround rods 2? within the casings ci and are compressed between collars 62, and the removable plugs ell which serve to hold the members in assembled position. The lower ends of these cam rods 28 are all attached to a common plate 65 by means of nuts 65a. Attached to the central portion of plate S5 is a rod 66, the lower end of which is pivotally attached to the foot treadle 6l. The inner end of this treadle @il may be pivoted in the frame i6, as at 63, and is normally held in an elevated position by the spring $39. Also plvotally attached to the treadle (5l is a second operating rod 1B, plvotally connectedat its other end to the link l l One end of link 'll is pivotally mounted on frame i5 by means of the pin 'l2 and the other end thereof, which 1s bifurcated and provided with slots i3, serves to operate the vertically reciprocating rod ld. The upper end of rod 14 has an arm 15 attached thereto by means of a set screw lli. Arm 'l5 carries an upper die member l1 and the other end of this arm is slidably mounted on algarve the stationary guide rod it iixed to plate it. 'The operating rod lll passes freely through openings in plates iii and t5, which serve to guide the rod lll.

The operation of the machine is as follows:

A camera bellows blank ld, such as illustrated in Fig. 9, and which has been previously formed in the shape of a :frustrum of. a pyramid with a small metal plate td, having an opening di fixed thereto, is placed over the end of rod it and the plates 5i and 52 so that the opening di in the plate titl fits over the end d@ of the rod .ds the foot treadle lil is pressed downwardly, rod is pulled down and plate @il moves all four of the cam rods 2d clown against the action or" their respective springs 63. This allows the tour slides ld to move inwardly toward the blank under the inucnce of the springs The side plates d, 3l, 38, are staggered vertically with respect to the central plates 5l and oi the mandrel and thus engage the correct portions of the sides oi. the bellows blank lil to start the folding operation, as illustrated in Fig. lll. At the same time the plungers i3 and buffers 33a move inwardly and hold the lower edges of the blank firmly against the sides ot die block ill.

Rod ld has been moved down by rod 'it through link li at the same time although in this position of the apparatus the upper die member ll has not yet come in contact with the top of rod 135. Upon further inward movement or. the side plates 36, 3l, and Sii, the side walls of the bellows blank begin to assume a partially folded position, as illustrated in Fig. l1, and die member lll, having a central opening to receive the section itl of rod d5. has moved into contact with plate di? attached to blank ls. This necessarily reduces the overall height of the blank 'l and, as this reduction takes place, the side plates dt, 3l and do, the

central rod d5, and central plates t and 52 move downwardly against the action o their respective springs lll and Gil. Cam rods 2d are now out of contact with their roller followers 25 and the lull action of springs 2l forces the side plates against the walls of the blank ld in the position shown in Fig. e.

Continued compression by die member El iinally forces the several plates together, accompanied by a further slight inward movement of the side plates, with portions of the blank interleaved between the several plates as illustrated in Fig. l2. Figs. 4 and 5 illustrate positions Ywhich the several portions of the mechanism occupy when acting upon a blank, although the blank itself is not shown. The compression thus produced by the die member ll assures the production of permanent folds along predetermined lines without distorting the finished bellows.

Upon release of the foot treadle lil, the mechanism is returned to its original position by the various springs and the folded blank or bellows 82 is stretched to the position shown in Fig. 13 so that it may be'easlly removed from the mandrel. The nished bellows has the shape and appearance illustrated in Fig. 14.

It will be seen that the construction of the mandrel and side plates provides a plurality of sets of oatingly mounted plates which are adapted to move as the sheet material of the blank is folded. This affords a positive operation and yet prevents tearing or marrlng of the blank, as well as assuring that every blank will be folded in the same manner.

Slides I9 may be moved inwardly by a positive comming action, if desired, although for folding relatively exible material, I preferto employ springs for this purpose to avoid marring the material. Although the blanks 19 are preferably previously scored, this is not essential.

The side plates may be of any suitable shape either all alike, or arranged in pairs, as illustrated (Fig. 2), depending on the character of the folding operation to be performed. Where the blank does not have a plate such as 80 ail'lxed to it, an additional plate may be mounted on the upper end of rod 45. Many other modifications of the specific embodiments of my invention illustrated in the drawings may be employed aswill be apparent to those skilled in the art.

'I'he terms and expressions which I have employed are used asterms of description and not of limitation, andl have no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

I claim:

1. Apparatus of the character described comprising means for supporting a hollow blank of material having a polygonal shape at points thereon spaced apart from each other, and means cooperating with said supporting means for folding said blank along predetermined lines into the shape of a bellows.

2. Apparatus of the character described comprising a mandrel for supporting a hollow blank of material, said mandrel contacting only portions of the blank before folding, and means cooperating with said mandrel for folding said blank along predetermined lines into the shape of a completely collapsed bellows.

3. Apparatus for folding a blank of sheet material comprising means for supporting said blank but movable in a direction at right angles to the direction of support, and means arranged to cooperate with said supporting meansv for pressing unsupported portions of Vthe blank about said supporting means to fold said blank along predetermined lines into a bellows.

4. Apparatus for folding a blank of sheet material having a polygonal shape, comprising means for supporting said blank but movable in a direction at right angles to the'direction of support, and means arranged to cooperate with said supporting means for folding said blank along predetermined lines, said last named means being movable in a direction at right angles -to the main line of folding. l 5. Apparatus for-folding a hollow blank of sheet material comprising means movable longitudinally of the blank for supporting said blank at spaced points throughout the circumference thereof, and means arranged to cooperate with said supporting means for folding said blank about said supporting means along predetermined lines. r

6. Apparatus for folding a hollow blank of sheet material comprising means movable longitudinally of theblank for SupDOrting said blank, means also movable longitudinally of the blank arranged to cooperate with said supporting means for folding said blank about said supporting means along predetermined lines, and means for,

moving said two means longitudinally of the blank simultaneously to assist the folding action thereof.

'7. In apparatus of the character described, a mandrel comprising a plate-like member movable in a direction substantially normal to its plane for supporting the interior of a hollow blank throughout its circumference, and means for cooperating with said mandrel to fold said blank about said mandrel.

8. Apparatus for folding a blank of sheet material comprising non-rotatable means for supporting said blank, and means arranged to cooperate with said supporting means for folding said blank along predetermined lines, said last named means comprising a plurality of plate-like members movable edgewise and also movable in a direction substantially normal to their planes.

9. In apparatus of the character described, -a mandrel comprising a plate-like member movable in a direction substantially normalto its plane, means for preventing rotation of said member, and means for cooperating with said-mandrel t lfold a blank of sheet material placed on said mandrel, said means comprising a plurality of plate-like members movable edgewise and also movable ina direction substantially normal to their planes.

10. In apparatus of the character described, a mandrel comprising a plate-like member movable in a direction substantially normal to its plane, means for cooperating with said mandrel to fold a blank of sheet material placed on said mandrel,

said means comprising a plurality of sets of substantially parallel plate-like members movable edgewise and also movable in a direction substantially normal to their planes, and means for moving the members of said cooperating means edgewise toward said mandrel.

1l. In apparatus of the character described, a mandrel comprising a plate-like member movable in a direction substantially normal to its plane, means for cooperating with said mandrel to fold a blank of sheet material placed on said mandrel,

means for cooperating with said mandrel to fold a blank of sheet material placed on said mandrel, said means comprising a plurality of plate-like members movable edgewise and also movable in a direction substantially normal to their planes,

means for moving the members of said cooperating means edgewise toward said mandrel, and a die member for subsequently striking a blow to move said plate-like members toward each other.

13. In apparatus of the .character described a mandrel comprising a plate-like member adapted to move in a direction substantially normal to the plane thereof. a plurality of sets of platelike members, constructed and arranged to move relative to each other in a direction substantially normal to their planes, and means for moving .said sets of members edgewise toward said mandrel.

14. In apparatus of the character described a mandrel comprising a plate-like member adapted to move in a direction substantially normal to the plane thereof, a plurality of sets of plate-like members, constructed and arranged to move relative to each other in a direction substantially normal to their planes, means for moving said sets of members edgewise toward said mandrel,

and die means Vfor subsequently moving all of said plate-like members together.

15. Apparatus as defined in claim 9 including spring means for urging said plate-like members apart.

16. Apparatus as defined in claim 13 including spring means for urging the plate-like members of each set apart.

17. Apparatus as dened in claim 13 in which the plate-like members of each set are normally staggered with respect to the mandrel member.

18. Apparatus for collapsing a hollow blank of sheet material into a bellows comprising a mandrel having a plate for supporting said blank which plate is movable in a direction substantially normal to its piane, a plurality of slides, a plurality of sets of plate members supported on said slides for movement in a direction substantially normal to their planes, means for moving said slides toward said mandrel, and means for moving said plate members towards each other after they have engaged said blank.

19. A method of folding a hollow polygonal shaped blank of material comprising exerting pressure on both the inside and outside of said vblank at points spaced apart from each other to start said folding, and subsequently compressing said blank by a force applied in a direction substantially at right angles to the direction of said pressure to completely collapse said blank into the form of a bellows.

4partly folded blank.

20. Folding apparatus comprising a mandrel. folding ymeans movable toward said mandrel, spring means for urging said folding means toward said mandrel, cam means for controlling the movement of the folding means by said spring means, and means for moving said mandrel :and folding means in a direction substantially at right angles to the first mentioned direction of movement of said folding means.

21. Folding apparatus comprising a mandrel, a plurality of sets of folding members, and means for simultaneously moving said sets of folding members towards said mandrel, said members and mandrel being resiliently mounted for movement towards each other in a direction at right angles to the first mentioned direction of movement of said folding members during a folding operation.

22. Apparatus as deilned in claim 3 in which means is provided for applying'pressure longitudinally of the blank to complete the folding of said blank.

23. Apparatus as dened in claim 9 ln which means is provided for resiliently urging the platelike members apart.

24. The method as defined in claim 19 in which the complete collapse of the blank into a bellows is obtained by sharply striking the top of the MAURICE M. BALSAM. 

